1. Field of The Invention
The present invention relates to an irrigation device for irrigating soils, to the process for manufacturing such irrigation device and to the process for using such irrigation device in irrigating soils. More particularly, the present invention relates to an irrigating device of the type in which a fixed or renewable source of water connected to the irrigating device is slowly, but continuously applied to the soil.
2. Discussion of the Prior Art
In the irrigation of soils, for example, to promote the growth of crops, water is generally supplied either to the surface of the soil or directly into the soil. This has typically been accomplished utilizing drip type devices or porous or perforated tubes through which it is possible to establish an equilibrium between the water source, or zone of excess moisture and the soil of insufficient moisture content.
However, particularly from the economic point of view, these prior art devices are expensive and bulky. In addition, it has been technically difficult when using porous or perforated tubes to ensure moisture equilibrium, because of the necessity for filtering the water from the water source to avoid blockage of the installation. In this regard, the inorganic salts present in water tend to block the holes or the pores of the porous or perforated tubes. This tendency is particularly noticeable in the case of intermittent operation of the irrigation devices. Therefor, it has proven necessary to install, generally near the irrigation orifices, means for avoiding such blockage. However, even when such filtering devices have been installed, it has been difficult to regulate the irrigation flow rate and in addition, frequent maintenance is required.
Still further, and particularly in connection with sloping terrains, it has been found that these types of irrigation devices require an excess consumption of irrigation liquid, which is believed to be primarily due to the fact that since the water tends to saturate the lowest zone of the terrain, it is necessary to supply additional irrigation liquid to the upper zones to ensure constant or uniform wetting of the soil.
Still further, in the case of surface installations of the irrigation devices, there are significant losses of irrigation liquid by evaporation and consequently, also an increased danger of blockage of the holes and pores of the irrigation tubes. This defect is particularly noticeable in regions which are very sunny and in regions with sandy terrain.